In FIG. 8, reference numeral 1 designates a portable telephone apparatus (child unit), numeral 2 an antenna for holding communication with a base station (or a parent unit), numeral 3 telephone control means for controlling the modulation/demodulation and the transmission/reception of a voice signal, numeral 4 a microphone, numeral 5 a speaker (or a headphone/earphone), numeral 6 operating means including keys and a liquid crystal display unit operated by the user, numeral 7 a battery, numeral 8 power supply means for supplying power to the portable telephone apparatus 1 from a charger 9, numeral 9 the charger for charging the portable telephone apparatus 1, and numeral 10 a power supply unit for generating the DC power of the voltage required for charging the portable telephone.
The operation of the conventional portable telephone apparatus will be described. When the portable telephone apparatus 1 is used, the user first turns the telephone off-hook by the operating means 6, and dials a desired number. This information is modulated by the telephone control means 3, and transmitted from the antenna 2 by radio to the base station (or the parent unit), and when it is connected to the called party, the apparatus enters a busy mode. A voice of the user in busy mode is input from the microphone 4, modulated by the telephone control means 3 and transmitted to the base station by radio. Conversely, a voice of the other party is inputted to the antenna 2 by radio from the base station, demodulated by the telephone control means 3 and outputted from the speaker 5. Upon termination of the busy mode, the apparatus is turned on-hook state by the operating means 6 thereby to disconnect the channel.
Also, in the case where the battery 7 is so consumed that it requires charging in busy mode, the charger 9 sets the portable telephone apparatus 1, and charges the battery 7 through the power supply means 8 from the power supply unit 10. The power supply means 8 may be an electrode-contacting type, but the contactless type using an induction coil is in current mainstay.